Thermal aging of polyvinyl chloride

This paper reports on the study of the thermal aging of the polyvinyl chloride used in high voltage cables. This study shows that thermal aging changes the electrical properties of the material. We notice that the higher the aging temperature is, the more important is the rate of degradation of the insulator. At the beginning of the aging process, there is a loss of the plasticizer. When the time of exposure to heat becomes important, the degradation is attributed to a progressive consumption of stabilizer with a change in colour and a release of chloridric acid. This phenomenon causes also cross-linking and reduction of insulator volume. The shrinking and the change in colour are the consequences of the material degradation.